Azure Sync Agent - Installation or upgrade is failing

Question

Azure Sync Agent - Installation or upgrade is failing

Santhosh Brahmadevara (NON EA SC ALT) 10 Microsoft Employee

Azure File Sync Agent upgrade failed.Even we installed new agent update KB from windows update but still it is not updating sync agent can not install agent already another agent version is there.As we got warning like soon agent version 20.0 is expiring.

kagiyama yutaka 5,410 Reputation points

2026-07-30T13:37:33.38+00:00

Could you add a bit more info about the Windows Server version, the current agent version, and the output of Get‑StorageSyncServer? That would help.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T13:39:44.31+00:00

Sure windows version 2025 datacenter edition
Current version is - AgentVersion : 20.0.0.0
kagiyama yutaka 5,410 Reputation points

2026-07-30T13:57:15.52+00:00

Thanks. I can’t yet see whether the issue is expiration metadata, OS mismatch, or an installer error... so if you can, please add the output of Get‑StorageSyncServer and the last part of the installer log.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:03:45.23+00:00

Please find ouput:
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:05:29.1+00:00

When i try to update from azure sync agent udpate:
kagiyama yutaka 5,410 Reputation points

2026-07-30T14:16:20.55+00:00

Thanks for the details. I think this is caused by Logman.exe blocking the agent update or by using an agent package that doesn’t match the Windows Server 2025 baseline.

Stopping Logman.exe (or removing old data‑collector sets) and then running the agent installer manually would fix it.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:39:37.01+00:00

Can you share the steps how to execute
Praveen Kumar Gudipudi 2,295 Reputation points Microsoft External Staff Moderator

2026-08-02T15:59:31.2633333+00:00
Hello Santhosh Brahmadevara,

Thank you for the information you shared. Based on the Get-StorageSyncServer output, the server is currently running Azure File Sync Agent version 20.0.0.0, the agent status is NearExpiry, and the automatic update has failed (UpdateSuccessful : False) without returning a specific error (UpdateError : 0). To further troubleshoot the issue, please try the following: Verify whether Logman.exe or any active Data Collector Sets are running by executing:

tasklist | findstr /I logman logman query

> > If any unnecessary or stale Data Collector Sets are running, stop them using: > ```yaml logman stop "<CollectorName>"

Download the latest Azure File Sync Agent from the Microsoft Download Center and run the installer manually using Run as Administrator, instead of relying on Windows Update. If the installation still fails, please collect the latest Azure File Sync installer log from:

C:\Users<username>\AppData\Local\Temp\

> > Look for files named `StorageSyncAgent*.log` and share the last 50–100 lines, especially any entries containing **"Return value 3"**, **"Error"**, or **"Failed"**. > Also check **Event Viewer** (**Windows Logs > Application**) for any **MsiInstaller** or **StorageSync** events at the time of the failed upgrade. > The installer log will help identify whether the failure is related to **Logman**, **Windows Installer (MSI)**, or another prerequisite. Once you share the log, we can help determine the exact root cause and the appropriate resolution.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-08-03T11:01:28.4233333+00:00
@Praveen Kumar Gudipudi Sure will execute command and will share you the output.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-08-03T11:19:58.5833333+00:00

@Praveen Kumar Gudipudi :logman query -ets output
C:\Windows\System32>msiexec /p "C:\Path\StorageSyncAgentPatch.msp" /L*v "C:\Temp\StorageSyncAgentUpdate.log"

C:\Windows\System32>tasklist | findstr /I logman

logman.exe 7284 Services 0 9,428 K

logman.exe 8516 Services 0 9,668 K

C:\Windows\System32>logman query

Data Collector Set Type Status

AFSKERNELMODETRACESESSION Trace Running

AFSUSERMODETRACESESSION Trace Running

GAEvents Trace Stopped

RTEvents Trace Stopped

Server Manager Performance Monitor Counter Stopped

The command completed successfully.

C:\Windows\System32>logman query -ets

Data Collector Set Type Status

AppModel Trace Running

CimFSUnionFS-Filter Trace Running

DiagLog Trace Running

Diagtrack-Listener Trace Running

EventLog-Application Trace Running

EventLog-System Trace Running

FilterMgr-Logger Trace Running

Microsoft-StorageSync-Filter-Log Trace Running

Microsoft-StorageSync-Filter-Trace Trace Running

Microsoft-StorageSyncGuard-Filter-Log Trace Running

Microsoft-Windows-Dedup-Filter-Log Trace Running

Microsoft-Windows-Dedup-Filter-Trace Trace Running

Microsoft-Windows-Rdp-Graphics-RdpIdd-Trace Trace Running

NtfsLog Trace Running

ReFSLog Trace Running

UAL_Usermode_Provider Trace Running

UBPM Trace Running

WdiContextLog Trace Running

MpWppCoreTracing-20260731-111353-00000003-100000000 Trace Running

SCM Trace Running

F589D420-8B9A-40A2-95A8-DBB27ED17997 Trace Running

BE235AAC-AC9D-4DDC-9FA6-D4C37AF837B7 Trace Running

D425B399-4B71-4151-8DAF-413F92A75EC3 Trace Running

CldFltLog Trace Running

MpWppUpdateLogging Trace Running

MpWppTracing-20260731-111357-00000003-fffffffeffffffff Trace Running

1DSListener Trace Running

MSDTC_TRACE_SESSION Trace Running

TracingGuidsAPM Trace Running

TracingGuidsApmConnector Trace Running

TracingGuidsManaged Trace Running

TracingGuidsNative Trace Running

TracingGuidsScript Trace Running

WindowsAzure-GuestAgent-Metrics Trace Running

WindowsUpdate_trace_log Trace Running

Sense-Tracer-{656A75EF-E6D7-41D6-BCE7-112E5468B4D1} Trace Running

SenseIRTraceLogger Trace Running

Admin_PS_Provider Trace Running

WindowsAzure-GuestAgent-Diagnostic Trace Running

WindowsAzure-GuestAgent-Status Trace Running

UpdateSessionOrchestration Trace Running

MoUxCoreWorker Trace Running

OMS-UpdateRunProgress Trace Running

UAL_Kernelmode_Provider Trace Running

SHS-07312026-112503-7-1ff Trace Running

MA_ETWSESSION_WAD_e48c54b0_8323_4bb5_a488_1869be17c224_IaaS__AZNEUVFSAFS02 Trace Running

Terminal-Services-LSM-ApplicationLag-1596 Trace Running

NativeMetricsExtension_Provider Trace Running

MA_ETWSESSION_AzureMonitorAgent_5c43fb02_f836_402c_8f1f_698c5bf3f7e3_vfs_neu_prod_afs_2f209fe1_53c9_4eac_a473_df5b594684d3 Trace Running

9C22BEA1-7763-41D1-B8F3-62A6ECC9D7E4 Trace Running

The command completed successfully.

3 answers

Your answer

kagiyama yutaka 5,410 Reputation points

2026-07-30T13:37:33.38+00:00

Could you add a bit more info about the Windows Server version, the current agent version, and the output of Get‑StorageSyncServer? That would help.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T13:39:44.31+00:00

Sure windows version 2025 datacenter edition
Current version is - AgentVersion : 20.0.0.0
kagiyama yutaka 5,410 Reputation points

2026-07-30T13:57:15.52+00:00

Thanks. I can’t yet see whether the issue is expiration metadata, OS mismatch, or an installer error... so if you can, please add the output of Get‑StorageSyncServer and the last part of the installer log.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:03:45.23+00:00

Please find ouput:
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:05:29.1+00:00

When i try to update from azure sync agent udpate:
kagiyama yutaka 5,410 Reputation points

2026-07-30T14:16:20.55+00:00

Thanks for the details. I think this is caused by Logman.exe blocking the agent update or by using an agent package that doesn’t match the Windows Server 2025 baseline.

Stopping Logman.exe (or removing old data‑collector sets) and then running the agent installer manually would fix it.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:39:37.01+00:00

Can you share the steps how to execute
Praveen Kumar Gudipudi 2,295 Reputation points Microsoft External Staff Moderator

2026-08-02T15:59:31.2633333+00:00

Hello Santhosh Brahmadevara,

Thank you for the information you shared. Based on the Get-StorageSyncServer output, the server is currently running Azure File Sync Agent version 20.0.0.0, the agent status is NearExpiry, and the automatic update has failed (UpdateSuccessful : False) without returning a specific error (UpdateError : 0). To further troubleshoot the issue, please try the following: Verify whether Logman.exe or any active Data Collector Sets are running by executing:

tasklist | findstr /I logman logman query

> > If any unnecessary or stale Data Collector Sets are running, stop them using: > ```yaml logman stop "<CollectorName>"

Download the latest Azure File Sync Agent from the Microsoft Download Center and run the installer manually using Run as Administrator, instead of relying on Windows Update. If the installation still fails, please collect the latest Azure File Sync installer log from:

C:\Users<username>\AppData\Local\Temp\

> > Look for files named `StorageSyncAgent*.log` and share the last 50–100 lines, especially any entries containing **"Return value 3"**, **"Error"**, or **"Failed"**. > Also check **Event Viewer** (**Windows Logs > Application**) for any **MsiInstaller** or **StorageSync** events at the time of the failed upgrade. > The installer log will help identify whether the failure is related to **Logman**, **Windows Installer (MSI)**, or another prerequisite. Once you share the log, we can help determine the exact root cause and the appropriate resolution.
Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-08-03T11:01:28.4233333+00:00

@Praveen Kumar Gudipudi Sure will execute command and will share you the output.

Answer 1

For an Azure File Sync agent that is on v20.0 and showing an expiration warning, use this path:

Verify whether the server has the expiration metadata applied. Run these commands in an elevated PowerShell session:
```
   Import-Module "C:\Program Files\Azure\StorageSyncAgent\StorageSync.Management.ServerCmdlets.dll"
   Get-StorageSyncServer
```
Check the AgentExpirationDate value.
If AgentExpirationDate is empty or not set, test connectivity.
```
   Import-Module "C:\Program Files\Azure\StorageSyncAgent\StorageSync.Management.ServerCmdlets.dll"
   Test-StorageSyncNetworkConnectivity
```
If connectivity problems are reported, fix those first. Auto Update requires the expiration metadata to reach the server.
Manually install the update if Auto Update or Windows Update did not complete the upgrade. For v20.1:
- It is available through Microsoft Update for servers currently running v20.0.
- AfsUpdater.exe does not work for v20.1 installation.
- Existing installations can be updated by downloading the package from Microsoft Update or Microsoft Update Catalog and installing it manually.
After extracting the CAB, run from an elevated command prompt:
```
   msiexec.exe /p packagename.msp REINSTALLMODE=OMUS REINSTALL=StorageSyncAgent,StorageSyncAgentAzureFileSync,StorageSyncAgentGuardFilter,StorageSyncAgentUpdater /qb /l\*v KB5056953.log
```
If the update appears stuck or hangs during install, check for the known Logman.exe issue. Symptoms include:
- AfsUpdater.exe hangs at installing updates
- installation hangs at Stopping monitoring agent
Fix:
- Open Task Manager
- End the LogMan process
- Repeat until all LogMan processes are stopped
- Let the agent update continue

Check whether a restart is blocking completion. Run:

   Import-Module "C:\Program Files\Azure\StorageSyncAgent\StorageSync.Management.ServerCmdlets.dll"
   Get-StorageSyncServer

If RebootNeeded is True, restart the server to complete the upgrade.

If installation still fails, review the installer logs. Default log location when installed on C::
```
   C:\Program Files\Azure\StorageSyncAgent\InstallerLog
```
Look for:
- AfsAgentInstall for MSI installs
- AfsUpdater for MSP update installs
Search near the end of the log for failure codes such as 1603.
If the server was upgraded to a different Windows Server version, do not try to reuse the old agent package. The Azure File Sync agent package is OS-specific. For an OS upgrade, the supported path is:
- uninstall the Azure File Sync agent
- restart the server
- upgrade Windows Server
- install the agent package that matches the new OS version
Do not unregister and re-register the server during the OS upgrade, because that can orphan tiered files.
For expired-agent remediation, avoid these actions:
- Do not unregister the server
- Do not uninstall and reinstall the agent as a first fix
- Do not run Reset-StorageSyncServer
These actions can break endpoints, lose local sync state, or force a full re-sync.
If there are no connectivity problems and AgentExpirationDate is still not set, contact Azure File Sync support.

References:

Answer 2

Hello Santhosh Brahmadevara (NON EA SC ALT),

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that your Azure Sync Agent is failing during installation or upgrade.

The best practice method is to either patch the existing agent using Microsoft Update/Microsoft Update Catalog/AfsUpdater, or, if patching fails, uninstall only the Azure File Sync agent, restart the server, and install the latest OS-specific agent without unregistering the server or deleting server endpoints. - https://learn.microsoft.com/azure/storage/file-sync/file-sync-release-notes

What you can do is to:

Stop attempting to install the new MSI over the existing agent.
Check whether the previous update is pending a reboot.
Validate whether Auto Update failed because the agent expiration metadata or network connectivity is blocked.
Apply the correct Microsoft Update Catalog/MSP package for the server OS, or use Microsoft Update/AfsUpdater.
If the update still fails, safely uninstall and reinstall the latest matching OS-specific Azure File Sync Agent without unregistering the server.

After applying the correct update path, the Azure File Sync agent should upgrade successfully, the expiration warning should clear after the server reports the new agent version, and the existing server registration/sync endpoints should remain intact. Do not unregister the server, because unregistering can break the trust relationship and may cause avoidable sync/tiered-file recovery issues. Microsoft specifically warns not to unregister and re-register during agent/OS upgrade scenarios because this can lead to orphaned tiered files. - https://learn.microsoft.com/azure/storage/file-sync/file-sync-release-notes

I hope this is helpful. Please! Do not hesitate to let me know if you have any other questions, steps or clarifications.

Please do not close the thread by upvoting and accepting the answer if any part of it is helpful.

Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-30T14:42:12.8766667+00:00

Hi @Sina Salam There is no pending reboot.

Answer 3

kagiyama yutaka 5,410

You can stop logman.exe from an elevated PowerShell using Stop-Process -Name logman -Force. amd If there are any old data‑collector set still hanging around, clean them up with logman query / logman delete. After that, run the Azure File Sync agent MSI manually — just make sure it’s the Windows Server 2025 package. That lets the update go through without rolling back.

Santhosh Brahmadevara (NON EA SC ALT) 10 Reputation points Microsoft Employee

2026-07-31T08:42:34.13+00:00

@kagiyama yutaka Can you please help in the steps how to update.
kagiyama yutaka 5,410 Reputation points

2026-07-31T12:21:52.81+00:00

The fastest and most reliable path at this point is opening a Microsoft support ticket. Windows Server 2025 + AFS Agent upgrade cases sometimes need backend checks, so if the logman cleanup isn’t straightforward on your side, a ticket is the safest option. The support can check the exact blocker.